Every week, a client asks us which miner offers the best value. The answer always depends on how long they plan to run it and what they pay for electricity. Here is a simplified model we use in our Power Efficiency Audits, using figures typical for a Daegu commercial facility in mid-2025.
Assumptions
- Electricity rate: ₩115/kWh (commercial, Daegu region)
- Operating hours: 24/7 (8,760 hours/year)
- Repair reserve: 8% of purchase price annually for mid-tier, 4% for high-tier
Three Models Compared
Used Antminer S19j (90 TH/s, ₩1.8M purchase, 30 J/TH)
Annual electricity: 90 × 30 × 8,760 / 1,000,000 × 115 = ₩2,714,700
24-month electricity: ₩5,429,400
Repair reserve (2 years): ₩288,000
Total 24-month cost: ₩7,517,400
Cost per TH over 24 months: ₩41,763/TH
Used Whatsminer M30S (88 TH/s, ₩1.6M purchase, 34 J/TH)
24-month electricity: ₩5,988,672
Repair reserve: ₩256,000
Total: ₩7,844,672
Cost per TH: ₩44,572/TH
New Antminer S19 XP (140 TH/s, ₩5.5M purchase, 21 J/TH)
24-month electricity: ₩5,512,440
Repair reserve: ₩440,000
Total: ₩11,452,440
Cost per TH: ₩40,889/TH
The Surprise
Despite costing three times more upfront, the S19 XP delivers the lowest cost-per-TH over 24 months at this electricity rate. The used S19j looks cheapest to buy but costs more per terahash-hour when you include power.
This flips at lower electricity rates. Below roughly ₩70/kWh, the used S19j wins on total cost. That is why we never publish a universal “best miner” list — the right answer is always specific to your facility.